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Discussion Starter #1
I've rebuilt my carb and the car is such a different machine. It fires RIGHT up even on a cold morning. Idle is smooth, calm and consistent.

Now the only thing that I can't figure out is the damn TSP thing. It's that solenoid that moves the throttle open under certain conditions, not sure which though.

I had read about it before but now that I need it, of course I can't find it. I own the five-volume Ford shop manuals and a clymer, but nothing.

Another question, if this is supposed to open the throttle to the idle position when the key is on RUN, the. What is the other screw on the idle tang for?!

Help me out here! It's a 1977 Lincoln Mark V with the 460 and Motorcraft carb.

Thanks
 

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For extra throttle opening when.
engine see's a load such as air cond. on.
set idel hot with all acc's on by in, no a/c on reg. carb screw
 

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Discussion Starter #3
On by in?

Ok this is what I figured. Jeez I thought motorcycle carbs were brilliant but I see that when carbs were the only choice for getting anywhere, they thought of a solution to EVERY problem! The auto-choke is so refined, all I have to do is pump the throttle once before starting and even on a cold day it jumps and goes.

Should ACC. idle also be 650rpm, like ACC. Off curb idle? (In Drive)

Thanks for explaining this.
 

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You must be an excellent rebuilder! I have the '76 truck manuals. Coverage is also minimal here on TSP. Not all trucks in '76 had one. There is a little in the engine book (fuel section), a little in volume 5 under "engine systems required maintenance", and a reference to it on the emission control label on the engine. It seems like the vehicles with A/C had one.:confused: On the GM vehicles it increased the throttle opening at idle when the A/C was on to maintain the RPMs.
 

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Discussion Starter #5
Thanks for that. I've been a moto mechanic for over a decade, and this is my first auto carb rebuild. Done plenty of car work before but this is new ground.

Ok so according to this sticker, the car should idle at 525rpm, but when you turn the A/C on, it should raise to 650, correct?

What other accessories need to be on and what setting should I have on as far as ventilation? I want to be sure this is done right, including the bowl vent setting.

Thanks!!
 

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Discussion Starter #6
Hm, the TSP doesn't shut off. It is constantly holding outward, unless the key is off, then it retracts.

What sensor or wire would I look at if the TSP can't tell that the A/C is on?
 

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I'm a bit unsure about interpreting the engine sticker. You may be correct. It looks like they show the 525 in neutral and the 650 in drive. The largest accessory load on the engine which would affect the idle would be the A/C compressor, so there may not be anything else to consider.(?)
As far as the bowl vent valve goes, the truck shop manual says it should be open to the carbon canister when the engine is off, and closed when the engine is operating. It should be adjusted with the carburetor installed on the vehicle.
Thanks for that. I've been a moto mechanic for over a decade, and this is my first auto carb rebuild. Done plenty of car work before but this is new ground.

Ok so according to this sticker, the car should idle at 525rpm, but when you turn the A/C on, it should raise to 650, correct?

What other accessories need to be on and what setting should I have on as far as ventilation? I want to be sure this is done right, including the bowl vent setting.

Thanks!!
 

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Your first sentence made me think of something else. Some gasoline engines had a way of "dieseling" or doing "run on" after the ignition was turned off. In order to stop them the manufacturer had to provide a method of completely cutting off the air flow by closing the throttle butterflies completely. I'm wondering if this could be a function of the TSP.(?)
I'm unsure where the electrical signal to the TSP originates. That should show somewhere on the wiring diagram.
Hm, the TSP doesn't shut off. It is constantly holding outward, unless the key is off, then it retracts.

What sensor or wire would I look at if the TSP can't tell that the A/C is on?
 

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.......what he said.....X2
 

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Discussion Starter #10
That makes sense but it doesn't.

Yes the bowl needs to vent when the engine is off, but the manual says to adjust idle via the screw on the tang. It never mentions adjusting the TSP or how, all it ever says in any manual is "make sure it's hard when on and soft when it's off. If it ain't, t'row 'er 'way an' getcha nudder one."

Also, if this were true, that it should always be on, then why is there two idle settings? One says with TSP on the other says off.

I believe that regular idle is 525 and it raises to 650 to compensate for the extra load.

Since the sticker says that "TSP-Off idle" is lower than regular curb idle, it proves that the TSP MUST raise the idle.
 

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I admit that more clarification is needed. I've got a 4350 rebuild coming up on my truck. I hope that I can get it done right also. I'll be doing more research on it. If something gets clarified, I'll re-post.
 

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Discussion Starter #12
Are you doing your own rebuild? I considered letting somebody else do it but.... they wanted the carb off of the engine, and I'd have to do the final adjustments and tune myself. Then what's the point? Oh, and on top of it, he was asking $300 starting!!!!!!!!!!!

When I charge $300+ for motorcycle carbs, they have at least three carbs and it includes synchronizing the throttle plates, adjusting valves and air/fuel mix, then parts additional.

It was so easy to rebuild it myself I just couldn't see where the amount of hours added up to make that kind of bill.

I've considered starting in the auto repair business. I'll grease your wheel bearings but you have to remove them and bring them to me then install them yourself. $100 per bearing, grease additional. Oh and as for my windshield wiper cleaning service, if you have to ask, you can't afford it.
 

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Yes, I do my own work. Through most of a lifetime, I've found that to be the best way in the long run. I learn what I need to know to do the job (even though it's hard to find the info. & parts sometime), buy the needed tools, and do the work. I've rebuilt other automotive carburetors, so I'm assuming that I can also learn the 4350.
 

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From memory you disconnect the tsp and adjust idle to 525. Connect the tsp, open throttle to make sure it extends, then adjust tsp for idle speed 650. Is there so engine don't run on when you shut it down
 

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Discussion Starter #15
WOW that is the most sensible take I've heard on this yet. Now it makes complete sense! UNPLUG IT, duh.

I have the idle set to the tang right now. I'll get on that tomorrow when it's nice and warmed up!

I may be a little obsessive but I need every function of the carb just right. Thanks! You nailed it.
 

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Adding in some pictures of 2 4350’s with no tags the PO gave me for some examples since these posts have helped. Thanks for 460ford and FTE!.
‘77 F-150 Ranger 460 had a 4V, even in California! San Jose model with a non-catalyst sticker too. Researching all the PO’s handiwork and trying to figure it all out. Gonna grab 2 rebuild kits and hopefully part out or sell the other one. First carb rebuilds so I figured better to keep them for now hah!
On the carbs notice underneath notice the slightly different cutouts. Any clue why they’d remove a little more material or is just Different castings over the years for those plates?
91772
91774
 
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